Pimería Alta, a desert region in northwest Mexico and southwest United States that spans adjacent portions of the modern states of Sonora (Mexico) and Arizona. Stretching westward from the San Pedro River to the Colorado delta and the Gulf of California, and northward from the Altar-Magdalena drainage to the Gila River in Arizona, Pimería Alta comprises the northern Sonoran Desert and contains some of the desert's most characteristic vegetation. The name symbolizes both the Hispanic and Native American cultural heritage of the region. "The land of the northern Pimas" was so christened by Jesuit missionaries, who began systematic religious conversion activities in the area during the 1690s, building their mission compounds around indigenous settlement patterns. The Pimas were village-dwelling agriculturalists who spoke related dialects belonging to the Uto-Aztecan family of languages.
Since colonization the Piman and Hispanic settlers of Pimería Alta have lived under Spanish, Mexican, and North American rule. The Gadsden Purchase (Treaty of Mesillas) of 1854 divided Pimería Alta between Mexico and the United States. The O'Odham (meaning "people"—the Pima and Papago) of southwest Arizona and northwest Sonora and the Gila River Pimas maintain strong cultural traditions and a binational orientation to Mexico and the United States.
The authoritative work on political geography is Peter Gerhard, The North Frontier of New Spain (1982). Three excellent published primary documents are Juan Nentvig, Descripción geográ fica, natural, y curiosa de la provincia de Sonora, edited by German Viveros (1971), also in English as Rudo Ensayo, a Description of Sonora and Arizona in 1764, edited by Alberto Francisco Pradeau (1980).
Ignaz Pfefferkorn, Beschreibung der Landschaft Sonora (1795), also in English as Sonora: A Description of the Province, edited by Theodore E. Treutlein (1949).
Diego Bringas De Manzaneda y Encinas, Friar Bringas Reports to the King: Methods of Indoctrination on the Frontier of New Spain, 1796–1797, edited by Daniel S. Matson and Bernard L. Fontana (1977). The Bringas report is enhanced by the introduction by Matson and Fontana. Armando Hopkins Durazo, gen. coord., Historia general de Sonora, 5 vols. (1985), is an excellent historical synthesis.
Griffiths, James S. Beliefs and Holy Places: A Spiritual Geography of the Pimería Alta. Tucson: University of Arizona Press, 1992.
Officer, James E., Bernard L. Fontana, et. al. The Pimería Alta: Missions & More. Tucson: Southwestern Mission Research Center, 1996.
Jackson, Robert H. New Views of Borderlands History. Albuquerque: University of New Mexico Press, 1998.